A Charlotte missionary and a Samaritan's Purse-based doctor stricken with Ebola virus, and undergoing treatment in an isolation unit in Atlanta, have both tested clear of the virus and have been discharged from the hospital.

Officials at Emory University Hospital made the announcement Thursday morning during a press conference.

Nancy Writebol was released from the hospital on Tuesday and has gone to an undisclosed location to rest and spend time with her husband. She was not at the press conference on Thursday morning.

Writebol was one of two missionaries who contracted Ebola while serving in Liberia last month.

Dr. Kent Brantly was in Liberia serving with Samaritan's Purse, Writebol was serving with Serving in Mission (SIM), an international Christian mission organization.

Writebol and Brantly were brought back to the United States nearly three weeks ago and have been getting medical treatment at Emory University Hospital.

Brantly has been getting treatment in Atlanta for 20 days, Writebol for 17 days.

"After a rigorous course of treatment and testing, the Emory Healthcare team has determined that both patients have recovered from the Ebola virus and can return to their families and community without concern for spreading this infection to others," Bruce Ribner, MD, director of Emory's Infectious Disease Unit, said during the announcement.

Criteria for the patients' discharges were based on blood and urine diagnostic tests and standard infectious disease protocols.

Emory said its medical team maintained its extensive safety procedures throughout the treatment process and is confident the discharge of the patients poses no public health threat.

"The Emory Healthcare team is extremely pleased with Dr. Brantly's and Mrs. Writebol's recovery, and was inspired by their spirit and strength, as well as by the steadfast support of their families," said Ribner.

Dr. Kent Brantly was at Thursday morning's announcement.

"Today is a miraculous day. I'm thrilled to be alive, well and reunited with my family," he said.

Brantly, 33, went to Liberia with his wife and two children last year to serve a two-year fellowship through Samaritan's Purse post-residency program.

He was there initially to practice general medicine. But when the Ebola outbreak began, he took on the role of medical director for the Samaritan's Purse Ebola Consolidated Case Management Center in Monrovia.

He says the group received their first Ebola patient in June and the group was prepared and took every precaution to protect themselves while providing treatment.

He says when things got worse, he took his wife, Amber, and the couple's children to the airport to return to the United States. Three days later, he became sick.

"I woke up feeling under the weather, and then my life took an unexpected turn as I was diagnosed with Ebola Virus Disease," he said. "As I lay in my bed in Liberia for the following nine days, getting sicker and weaker each day, I prayed that God would help me to be faithful even in my illness, and I prayed that in my life or in my death, He would be glorified."

"I did not know then, but I have learned since, that there were thousands, maybe even millions of people around the world praying for me throughout that week, and even still today," he continued. "I cannot thank you enough for your prayers and your support. But what I can tell you is that I serve a faithful God who answers prayers."

He said he plans to go away with his family to reconnect, decompress and continue to heal.

"My dear friend, Nancy Writebol, upon her release from the hospital, wanted me to share her gratitude for all the prayers on her behalf. As she walked out of her isolation room, all she could say was, 'To God be the glory.' Nancy and David are now spending some much needed time together."

Writebol, 59, and her husband David were in Monrovia, Liberia when she was infected with the Ebola virus.

Since August 2013, the Writebols have worked for the SIM group, which worked with Samaritan's Purse.

Writebol was working as the personnel coordinator, helping SIM missionaries entering the country. She also served as a certified nursing assistant.

Her duties at the clinic included disinfecting doctors and nurses entering or leaving the Ebola treatment area. Her husband was the technical services manager at the same facility. Nancy was diagnosed with Ebola on July 25, 2014.

"Today I join all of our Samaritan's Purse team around the world in giving thanks to God as we celebrate Dr. Kent Brantly's recovery from Ebola and release from the hospital," Franklin Graham, president of Samaritan's Purse said early Thursday morning.

"Over the past few weeks I have marveled at Dr. Brantly's courageous spirit as he has fought this horrible virus with the help of the highly competent and caring staff at Emory University Hospital. His faithfulness to God and compassion for the people of Africa have been an example to us all."

"I know that Dr. Brantly and his wonderful family would ask that you please remember and pray for those in Africa battling, treating and suffering from Ebola. Those who have given up the comforts of home to serve the suffering and the less fortunate are in many ways just beginning this battle," Graham continued.

"We have more than 350 staff in Liberia, and others will soon be joining them, so please pray for those who have served with Dr. Brantly - along with the other doctors, aid workers and organizations that are at this very moment desperately trying to stop Ebola from taking any more lives."

Nancy Writebol's husband, David, and several other SIM-based missionaries were brought back to Charlotte about a week ago. None of the missionaries were showing any signs of Ebola symptoms, but were being held in quarantine as a precaution.

Once he was cleared, David Writebol made a brief appearance at a morning service at Calvary Church in Charlotte, where he is a church member. Church officials say he was welcomed with a standing ovation and prayer for Nancy.

After attending the church service, Writebol went to Atlanta to reunite with his wife.

"I have had the great joy to be able to look through the isolation room glass and see my beautiful wife again. We both placed our hands on opposite sides of the glass, moved with tears to look at each other again," Writebol said after getting to Atlanta.

"She was standing with her radiant smile, happy beyond words. She is continuing to slowly gain strength, eager for the day when the barriers separating us are set aside, and we can simply hold each other. We prayed together over the intercom, praising our great and mighty God for his goodness to us."

Thursday morning, David Writebol released a statement about Nancy being released from the hospital.

"Nancy joined the ranks of a small, but hopefully growing number of survivors of the Ebola Virus Disease (EVD) when she walked out of the Emory University Hospital Isolation Unit on Tuesday afternoon," he said. "Nancy is free of the virus, but the lingering effects of the battle have left her in a significantly weakened condition. Thus, we decided it would be best to leave the hospital privately to be able to give her the rest and recuperation she needs at this time."

"During the course of her fight, Nancy recalled the dark hours of fear and loneliness, but also a sense of the deep abiding peace and presence of God, giving her comfort," he continued.

"She was greatly encouraged knowing that there were so many people around the world lifting prayers to God for her return to health. Her departure from the hospital, free of the disease, is powerful testimony to God's sustaining grace in time of need."

The Mecklenburg County Health Department says it will not comment on individual missionaries health or release from quarantine.

"Once all the missionaries are all released from quarantine we will work with SIM on informing the community," officials told WBTV.

Copyright 2014 WBTV. WGCL-TV and CNN contributed to this report. All rights reserved.